<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>3-前置后置案例</title>
	</head>
	<body>
		<script type="text/javascript">
			/**
			 * 前置递增：先自加，后返回值
			 * 后置递增：先返回值，再自增
			 */
			var x = 3;
			var y =5;
			
			var z = ++x + y++ + 20;
			//      4+5+20 = 29
			//x = 4
			//y= 6
			console.log("z::"+z);
			console.log("x::"+x);
			console.log("y::"+y);
		</script>
	</body>
</html>
